In the machining chamber of a machining device of this kind, workpieces are blasted by means of a compressed air-blasting medium mixture. This type of machining can easily lead to injury to the person performing it and is also health hazardous in particular if the workpieces contain hazardous substances as is the case, for example, with quartz (danger of silicosis). This material is often used, in particular with dental workpieces. In the machining chamber these types of machinings can be carried out so that they are safe for the operator and the environment because, on the one hand, the machining chamber is closed--which purpose is served by gloves or sleeves in the region of the gripping holes, the collar rings of the gloves or sleeves each being secured in a mounting provided on the edge of the opening. In modern machining devices the machining chamber can be connected to a suction device by means of which the dust, in particular health hazardous dust, e.g. quartz dust, can be sucked off and collected.
With the known mountings for securing the gloves or sleeves, installation is awkward. A great deal of work is thus necessary to exchange the gloves or sleeves or replace them with new ones. In practice this leads the operator to avoid and therefore refrain from doing this, which results in some types of machining being carried out improperly which is not only dangerous but can also impair the quality of machining.